Aaron Chote
PhD Student - Imperial College, London
Project Title: ZrO2 Corrosion Layers and their Grain Boundary Networks
Aaron Chote completed his BSc (Hons) and MSc in Chemistry and Polymer Chemistry, respectively, at the University of Warwick, where he achieved best dissertation in his MSc for his work on ‘Transdermal Delivery of Cannabinoids: Insights from Molecular Dynamics Simulations of CBD and THC Permeation through Skin-Lipid Bilayers’. Aaron’s PhD project is co-sponsored by Imperial and EPSRC and looks at the effect that lithium has on ZrO2, and the underlying Zircaloy-4 metal.
Zircaloy-4 is the principal alloy employed as the cladding material in the UK’s only pressurised water reactor (PWR). Lithium is an additive in the coolant water of PWRs but the effect of lithium on the microstructural evolution and texture of the growing ZrO2 layer is not well-understood.
By looking at lithiated and non-lithiated ZrO2 layers from autoclaved Zircaloy 4 samples (oxidised for 105 days at 573K, 140MPa in 70-ppm lithiated water) using precession electron diffraction, insight into the grain boundary plane distribution and grain boundary character distribution is being investigated. Atom probe tomography is being used to understand lithium’s segregation behaviour in ZrO2 layers. Current results show that a change in thickness of the ZrO2 layer has been related to the underlying Zircaloy-4 grain orientation, along with the co-segregation of lithium and iron to grain boundaries.
“Doing a PhD opens your eyes to a world veiled in a cloak of inaccessibility and shows you the kind of person you are capable of being. It pushes you to really dig deep and flourish, whilst being exposed to some of the world’s best experts – it really is the opportunity of a lifetime.”